SUDBURY ENVIRONMENTAL STUDY
^ EMISSIONS OF SULPHUR OXIDES, PARTICULATES
AND TRACE ELEMENTS IN THE SUDBURY BASIN.
■i •*■'.*» ^
Keith C. Norton, Q.C.,
Gerard J. M. Raymond
SUDBURY ENVIRONMENTAL STUDY
EMISSIONS OF SULPHUR OXIDES, PARTICULATES AND TRACE
ELEMENTS IN THE SUDBURY BASIN.
Source Assessment Unit
Emissions Technology and Regulation
Development Section, Air Resources Branch
Ontario Ministry of the Environment
880 Bay Street, 4th Floor
Toronto, Ontario, Canada, M5S Iz 8
S.E.S. Coordination Office
Ontario Ministry of Environment
6th Floor, 40 St. Clair Ave. W.
Toronto, Ontario, Canada, M4V 1M2
Project Coordinator: E, Pich§
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TABLE OF CONTENTS
List of Tables i
List of Figures li
1. Introduction 1
2. Summary 5
3. Description of Sources and Processes 9
3.1 General 9
3.2 The Inco 381 m Stack and the Smelter
Building at Copper Cliff 9
3.2.1 Copper Circuit 10
3.2.2 Nickel Circuit 11
3.3 The Inco 19^^ m Stack and the Iron Ore
Recovery Plant Complex at Copper Cliff 12
3.3.1 Iron Ore Recovery and Pelletizer Plants 13
3.3.2 Nickel Refinery m
3.3.3 Sulphuric Acid Plants 15
3 A The Falconbridge 93 m Stack 15
^. Discussion of Emission Measurement Methods, Their
Frequency and Accuracy 17
5. Sulphur Dioxide Emissions 22
5.1 The Inco 381 m Stack 23
5.2 Inco Low Level Emissions 28
5.3 The Inco 19^ m Stack 29
5A The Falconbridge 93 m Stack 30
TABLE OF CONTENTS - Continued
6. Emissions and Size of Total Particulates 32
6.1 The Inco 381 m Stack 13
6.2 The Inco 19^^ m Stack M
6.3 The Falconbridge 93 m Stack $Q
6A Inco's Low Level Emissions 4l
6.5 Size of Emitted Particulates ft2
6.5.1 Particulate Size Measurements at
the Inco 381 m Stack 43
6.5.2 Particulate Size Measurements at
the Falconbridge 93 m Stack ^i
7. Emissions of Metals i|6
7.1 The Inco 381 m Stack 48
7.2 The Inco 19* m Stack 58
7.3 Low Level Emission from the Inco Smelter
7 A The Falconbridge 93 m Stack f 1
8. Emissions of Sulphuric Acid 65
9. References 67
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LIST OF TABLES
1. AVERAGE YEARLY EMISSIONS OF MAJOR POLLUTANTS IN THE
SUDBURY BASIN IN TONNES FOR THE PERIOD 1973-1981 6
2. YEARLY EMISSIONS OF SULPHUR DIOXIDE FROM MA30R INDUSTRIAL
SOURCES IN THE SUDBURY BASIN IN THOUSAND TONNES 23
3. SULPHUR DIOXIDE EMISSIONS FROM INDIVIDUAL PROCESSES TO THE
INCO 19^^ METRE STACK IN TONNES PER/DAY IN 1977 30
^. YEARLY EMISSIONS OF TOTAL PARTICULATES IN TONNES FROM
MAJOR INDUSTRIAL SOURCES IN THE SUDBURY BASIN FROM
1973 TO 1981 33
5. MEASURED AVERAGE PARTICULATE EMISSIONS FROM THE INCO 381 M
STACK IN TONNES/HOUR 35
6. PARTICULATE EMISSIONS FROM THE INCO 194 M STACK
IN TONNES/DAY 39
7. SUMMARY OF PARTICLE SIZE MEASUREMENTS AT THE INCO
381 M STACK «4
8. SIZE OF PARTICULATES EMITTED FROM THE FALCONBRIDGE
93 M STACK 45
9. AVERAGE EMISSIONS OF METALS FROM MAJOR SUDBURY
SOURCES IN KILOGRAMS/HOUR 47
10. AVERAGE EMISSIONS OF FIVE MAJOR METALS FROM THE INCO 381 M
STACK IN KILOGRAM/HOUR ^9
11. AVERAGE MEASURED EMISSIONS OF METALS AND OTHER
PARTICULATE POLLUTANTS FROM THE INCO 381 M STACK IN
12. COMPARISON OF IN-STACK AND IN-PLUME AVERAGE EMISSIONS
IN TONNES/DAY 59
13. EMISSIONS OF METALS FROM THE IRON ORE RECOVERY AND
NICKEL REFINERY PLANTS IN KILOGRAMS/DAY $0
14. AVERAGE LOW LEVEL EMISSIONS OF METALS FROM THE
INCO SMELTER AT COPPER CLIFF DURING TYPICAL PRODUCTION
RATES OF NICKEL BESSEMER MATTE AND BLISTER COPPER
IN KILOGRAMS/DAY ^2
15. EMISSIONS OF METALS FROM THE FALCONBRIDGE 93 M
STACK IN KILOGRAMS/DAY ^
16. ACID EMISSIONS FROM MAJOR INDUSTRIAL SUDBURY SOURCES
IN TONNES/HOUR $6
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LIST OF FIGURES
1. LOCATION OF MAJOR AIR POLLUTION SOURCES IN THE
SUDBURY BASIN IN ONTARIO 3
2. SULPHUR DIOXIDE EMISSIONS COMPUTED BY MASS
BALANCE VS EMISSIONS MEASURED AT THE INCO
381 M STACK 24
3. SO2 EMISSIONS VS ROASTER MATERIAL INPUT 26
4. SO2 EMISSIONS VS CONVERTER MATTE INPUT 27
5. TOTAL PARTICULATE VS SULPHUR DIOXIDE EMISSIONS 37
6. FREQUENCY DISTRIBUTION OF ERRORS FOR PARTICULATE VS
SULPHUR DIOXIDE EMISSIONS 38
7. IRON VS SULPHUR DIOXIDE EMISSIONS 51
8. FREQUENCY DISTRIBUTION OF ERRORS FOR IRON VS SULPHUR
DIOXIDE EMISSIONS 52
9. COPPER VS SULPHUR DIOXIDE EMISSIONS 53
10. FREQUENCY DISTRIBUTION OF ERRORS FOR COPPER VS SULPHUR
DIOXIDE EMISSIONS 54
11. NICKEL VS SULPUR DIOXIDE EMISSIONS ^5
12. FREQUENCY DISTRIBUTION OF ERRORS FOR NICKEL VS SULPHUR
DIOXIDE EMISSIONS 56
- Ill -
This report is based on results published in many reports, and appreciation
is extended to all individuals whose efforts have made this report possible.
Personnel from various process technology groups and laboratories of the
Inco Metals Company and Falconbridge Limited, and Sudbury Regional Office,
Laboratory Services Branch and Air Resources Branch staff of the Ministry of
the Environment contributed to the generation of the data compiled and
Special thanks are extended to Messrs, G. Wong and J. Marson for
performing calculations for this report, Messrs. R. Potvin, L, Fitz, E.T. Barrow,
C.B. Martin, Drs. M, Lusis and W. Chan for their critical review of this report.
The Sudbury Basin in Ontario is an area of major environnnental interest
because of large emissions of sulphur dioxide and particulates due to smelting
and mining activities. In 1973, the Ontario Ministry of the Environment
recognized the need for an evaluation of the impact of the smelting industries on
the area and initiated studies aimed at characterization of emissions, in terms of
both chemical composition and quantities, from the most significant sources in
the Basin. In 1977, a more comprehensive program was established at the Air
Resources Branch with the following objectives:
1. to define the sources and source strengths of atmospheric emissions
in the Sudbury Basin.
2* to determine the fate of these emissions.
.% to determine the ambient air concentrations of potentially hazardous
In essence, the study problem was the origin and fate of the pollutants, the
nature and quantity of the emissions, and then dispersion, chemical
transformation and ultimate deposition subsequent to being released to the
atmosphere. A more detailed description of the program is given in the Ministry
report ARB-27-82 ARSP (39).
This report deals with the emissions. The major emission sources in the
Basin are described in detail and the emissions of pollutants are quantified on the
basis of many reports issued in the last ten years by the companies which own
the processing plants in the area and the Ministry of the Environment.
The processing plants with the major air pollution sources in the Sudbury
Basin are all located within a distance of 15 kilometres from the city of Sudbury.
(the location of these plants is illustrated in Figure 1). They are associated with
two copper and nickel smelters (Inco Metals Company at Copper Cliff and
Falconbridge Limited in the town of Falconbridge) and the Inco Metals Company
nickel refinery - iron ore recovery plant complex at Copper Cliff, Emissions
from these sources account for almost all industrial emissions in the Basin.
During the eight years from 1973 to 1980, emissions from a number of
individual sources at both smelters were measured by the companies and
governments, and the combined emissions from these sources have been
considered as representative of all industricil emissions in the Basin. Most of the
emission measurements were done in stacks or ducts venting plant emissions to
these stacks. In the case of Inco, emissions escaping from the main smelter
building through windows and building ventilators were also measured.
A variety of measurement methods suited to a particular source or stack
were employed by various industry or government groups. These methods ranged
from rigorous source testing procedures as specified by the Ministry of the
Environment to unproven and experimental emission measurement techniques.
The observed inconsistencies and differences in the measured results were
partially attributed to the nonre present at iveness of some measurement methods.
Besides differences in the measurement methods applied at the same
source at various times, there were differences in the process conditions, and
particularly in the amount of materials processed in the measured plants. The
variations in the process conditions effected variations in the emission rates and
the results of the emission measurements. However, due to complexity of the
processes involved in smelting, there were difficulties in relating the effects of a
specific process (or changes in the operation of this process) on the totcU
FIGURE I. LnCRTlDN DP MRJDR RIR PDLLUTIDN
BQURCEB IN THE SUDBURY BR51N IN
- '^ -
emissions from the smelter or the plant. This in turn resulted in difficulties in
the analyses of the results measured at the same source at different times and in
arriving at the emissions rate which is most representative of the process.
The purpose of this report is to summarize and discuss all emission testing
carried out during the period from 1973 to 1980, interpret and correlate the
measured emissions with production wherever possible, and provide a technical
basis for estimation of emissions in the Sudbury Basin, This in turn is necessary
for the evaluation and analysis of air pollution in the Basin and consideration of
any abatement action by the industries of concern.
The most significant source of air pollution in the Sudbury Basin is the 381
metre stack at the Inco Copper Cliff smelter. Depending on the pollutant, this
source may contribute anywhere from 50% to over 80% of all emissions in the
Basin. The only exception is copper, which is also emitted in significant
quantities from other sources. In order of emission magnitude the other sources
of significant pollution in the area are the Inco 19^^ metre stack, the
Falconbridge 93 metre stack, and finally ventilators and windows which emit
unconfined emissions from Inco's main smelter building at Copper Cliff.
Emissions of almost all major pollutants from the Inco 381 m stack
increase proportionately with production activities in the smelter. It was
possible to demonstrate this relationship for this source because of the relatively
large number of measurements performed in the period from 1973 to 1980.
Corresponding data for the other sources in the Basin were not sufficient for a
similar experimental verification.
Emissions of selected major pollutants from the measured sources in the
Sudbury area are shown in Table 1. Maximum, average and minimum emissions
are shown wherever available.
Emissions of sulphur dioxide from the Inco 381 m stack have been measured
on a continuous basis since 1973, and were shown to change proportionately with
the level of production. The emissions of particulates, iron, nickel, and copper
from this stack as shown in Table 1 were calculated from linear correlations
between the measured emissions of sulphur dioxide and these species such that
TABLE 1: YEARLY EMISSIONS OF MA30R POLLUTANTS IN THE SUDBURY BASIN
IN TONNES FOR THE PERIOD 1973 - 1981
Inco 381 m
Inco 194 m
Two 45 m
Basis: 365 days x 24 hrs/day production.
Oxides of nitrogen emissions expressed as NO- = 3,281 tonnes.
Hydrogen chloride emissions = 530 tonnes.
Emissions of particulates, iron, copper and nickel from the 381 m stack are yearly values calculated from correlations
with sulphur dioxide emissions. Emissions of sulphuric add, lead and arsenic are average measured values.
Emissions ceased in April 1980, not included in average.
Except for INCO Smelter (low level), all sulphur dioxide emissions were obtained by mass balance calculations.
Annual low level ammonia emissions from Inco's iron ore recovery plant in 1977 was 4,219 tonnes.
they correspond to annual sulphur dioxide emissions. In this way, the effect of
production rates on emissions has been taken into account, and so the calculated
emissions as shown in Tables 1 and 10 are considered more representative of the
actual emissions than the individucil emissions measured in stack tests of short
duration shown in Table 11. Before selecting the straight-line correlations, a
number of linear and nonlinear relations were examined for the goodness of fit
through the experimental points plotted on the graphs. In the case of iron,
copper and nickel, the straight lines and exponentied curves provided reasonable
correlations of the data available; however, since the estimates from these
functions were not significantly different, it was decided to use the
mathematically simpler straight-line correlations. As is the case with any
function fitted through scattered experimental points, errors (or uncertainties)
are associated with the estimates of emissions of particulates, iron, copper and
nickel, calculated from the straight-line correlations in this report and these
errors must be taken into account when using the calculated emissions. In any
individual case, the variation from the straight-line estimate can be greater than
+ 100%, but is generally less than +75%. The indicated maximum, average, and
minimum in Table 1 are yearly values. Emissions during shorter periods in any of
the examined eight years could be either smaller or larger, depending on
production. Emissions from the other sources in Table 1 were measured in
shorter periods and are in some cases based on the results of one test only.
About 78% of all sulphur dioxide and 11% of all sulphuric acid emissions
are from the Inco 381 m stack; the estimates of total particulates indicate that
the corresponding contribution from this source is lower at 75^, while the
contributions to metal emissions are still smaller at 37-55% except for lead, and
arsenic which are mostly emitted from this source.
Up to April 1980, when the pelletizing plant, associated with the iron ore
recovery process was shut down, Inco's two ^5 m stacks at this plant were
significant sources of particulate and iron emissions in the Basin. The best
available emission data are based on a single testing survey of only one stack.
Hence, due to the paucity of data for this source, the emission rates presented in
Table I were not included in the average emissions from the Sudbury Basin. This
source is not expected to resume operation.
Emissions of oxides of nitrogen and hydrogen chloride were measured on
two occasions at the Inco 381 m stack, and because they were small in
comparison to sulphur dioxide and sulphuric acid, these measurements were
discontinued at this and other stacks in the Basin.
Ammonia emissions are low level emissions, occurring through losses to the
atmosphere via leaching and recovery buildings' ventilators. They are calculated
from losses in process and discharge streams on a monthly basis. Annual
emission for 1977 was the only available estimate at the time of writing.
The size of the emitted particulates is an important consideration in the
understanding the deposition of particulate pollutants and in determining the
airborne part of particulate emissions. Since most sources in the Sudbury Basin
are controlled and the majority of particulates are removed by electrostatic
precipitators at a source, it was expected and confirmed by testing that large
portions of the particulates in emissions are less than 10 micrometers (m |j ) in
3. DESCRIPTION OF SOURCES AND PROCESSES
The most significant sources of industrial emissions in the Sudbury Basin
are five stacks - the Inco 381 m and 19^ m stacks, the Falconbridge 93 m, and
prior to 1980, Inco's two ^5 m stacks. Before entering these stacks, emissions
from various industrial processes are cleaned of a large portion of particulate
pollutants by electrostatic precipitation and contain small and to a large extent
airborne particulates. These are called confined emissions, which after being
discharged are mostly carried away from stacks and are diluted considerably
with ambient air before impinging on the ground. Other emissions are
unconfined, since they escape various process fume collection steps in the ore
and metal processing. They are emitted through small stacks on building roofs,
windows and ventilators, and called low level emissions, impacting in the plant
vicinity and reaching the ground in a more concentrated form. They are difficult
to quantify and were measured by the company at Inco's Copper Cliff smelter
building only. However, this building is the most significant source of low level
emissions in the Sudbury Basin.
A detailed description of the processes described in this chapter was
presented in an earlier Ministry report (2^). The following is intended as a
summary of that information.
3.2 INCO'S 381 M STACK AND THE SMELTER BUILDING AT COPPER CLIFF
The 381 m stack emits gases from pyrometallurgical smelting processes at
Inco's Copper Cliff smelter. The outside diameters of this stack at the base and
at the top are 35.5 m and 15.8 m, respectively. About 157,000 cubic meters of
gas at a temperature of 130°C are emitted each minute from this stack. The gas
temperature increases with increasing production rates and can reach about
175 C when the smelter is operated at full capacity. Gases are received from
various processes via two inlet breachings situated opposite to each other at the
stack base, and are cleaned of most of the particulate pollutants by electrostatic
precipitators called Cottrells prior to entering the stacks.
Because of the large stack diameter, the positions of the two inlet
breachings and the location of the existing sampling platform, strict emission
measurements at this stack are long lasting, manpower intensive and expensive.
On occasions, the measurement methods were simplified at a cost of somewhat
The purpose of the smelting processes which emit pollution into this stack
is to make nickel and copper of appropriate purity in the form of nickel bessemer
matte and blister copper from suitably prepared ore concentrates. There are
two main circuits with associated process equipment - one of each for nickel and
copper. Nickel matte processing is considered a separate process, however,
since in comparison to ore roasting and smelting, it is not a major source of
emissions, this process will not be discussed any further.
3.2.1. COPPER CIRCUIT
Copper concentrate, mixed with sand, is smelted in a flash furnace,
producing copper matte, slag , and sulphur dioxide at about Z0% concentration in
the off-gases. These gases are first cleaned in scrubbers and a wet electrostatic
precipitator, then sent to the sulphur products plant for the production of liquid
sulphur dioxide. In case of an emergency, these gases may be directed to the 381
m stack via a bypass system. The gases rising from the handling operations of
- 11 -
the two melted products - slag and copper matte - are split, with the major
portion being emitted via a small stack on the roof of the building and the rest
directed to the 381 m stack. In addition to these major emissions, there are
fugitive emissions resulting from leakages in the scrubbers, sulphur dioxide
release from the scrubber liquid, temporary pressure increases in the furnace and
the periodic return of the converter slag.
Copper matte from this furnace is charged to copper converters to
eliminate the remaining iron and to produce blister copper which is then sent to
copper refinery for further refining. Converting is a batch process in which
oxygen enriched air is blown through the melted charge to produce oxides of iron
which react with silica and form slag. The main product of converting, blister
copper, is sent to the copper refinery for further processing. The main portion
of off-gases is sent to the 381 m stack via collection fume hoods and flues. Part
of the off-gases escapes from around the collecting hoods into the building and
outside through the roof ventilators as fugitive emissions.
3.2.2 NICKEL CIRCUIT
Nickel concentrate is first mixed with sand and then roasted in multi-
hearth roasters to remove moisture and a part of sulphur as sulphur dioxide.
Heating of concentrate on the roaster hearths is accomplished by the combustion
of natural gas and the oxidation of iron sulphide with air. This air along with
sulphur dioxide and entrained particulates is directed to the 381 m stack via
piping arrangements on the roasters' tops. Besides these confined emissions,
there are periodic fugitive emissions escaping through the inspection doors.
These emissions rise to and are emitted through the roof ventilators and the
building windows. Six roasters are operated in conjunction with one
The product of roasting, calcine, is fed to the reverberatory furnaces to
combine iron oxide with silicate and produce slag. Slag floats on the top of
matte which contains heavier sulphides of copper, nickel and iron. Combustion
of oil, sustained with oxygen enriched air, provides the necessary heat to
maintain the furnace contents in a molten state. The combustion gases with
entrained particulates and sulphur dioxide are conveyed via a reverb-header flue
to the 381 m stack. Unconfined fugitive emissions from this furnace originate
during the removal of matte and slag from the furnace, they are collected by
hoods and exhausted into separate vents. In addition, puffing emissions, escaping
the furnace through its brickwork during periods of increased pressure within the
furnace, and the emissions originating during the converter slag removal exit the
smelter building via the roof ventilators above the furnace. There are five
reverberatory furnaces of which three or four are usually operated at any one
Matte from these furnaces is fed to the nickel converters, where similar
operations to those in copper converting are carried out. After oxidation of iron
and formation of slag, the converter is rotated for skimming and discharging of a
high grade copper-nickel matte for casting and cooling. Emissions from various
steps - charging, blowing, skimming and pouring - are collected by hoods and
directed to the electrostatic precipitators and the 381 m stack. However, some
of these emissions escape around the hoods and from the building via ventilator
openings. Fourteen converters are normally used in the nickel circuit.
3.3 THE INCO 19» M STACK AND THE IRON ORE RECOVERY PLANT
COMPLEX AT COPPER CLIFF
The Inco 19^ m stack is the second largest source of industrial emissions in
- 13 -
the Sudbury Basin. Approximately 9500 cubic meters of gas at 150°C to 200°C,
containing metals, sulphur dioxide, and sulphuric acid are exhausted every
minute from this stack. The stack receives off-gases from Inco's iron ore
recovery plant, nickel refinery and three sulphuric acid plants. Similarly to
process off-gas treatment at the nickel smelter, emissions from these five plants
are cleaned of the majority of entrained particulates prior to entering the stack.
Cyclones, scrubbers, settling chambers, electrostatic precipitators and
combustion units are used for this purpose at the iron ore recovery plant,
electrostatic precipitators at the nickel refinery, and packed water scrubbers at
the three acid plants.
Emissions from the 19^ m stack were not measured directly in the stack,
but in the flues from the iron ore recovery, the nickel refinery and the acid
plants. These flues were not readily amenable to stack sampling and the
measurement methods had to be compromised and less rigorous procedures used
because of limitations in locating suitable sampling sites. Consequently, the
accuracy of measurements was affected and somewhat larger errors are
associated with the reported emissions from the 19^ m stack.
3,3.1 IRON ORE RECOVERY AND PELLETIZER PLANTS
There are four processes involved in iron ore recovery at the Inco plant:
roasting and reduction of pyrrhotite concentrate, leaching, recovery and
pelletizing. The purpose of these processes is to recover nickel from pyrrhotite
concentrate received from the Inco smelter and to prepare iron rich pellets for
marketing. In the roasting step, most of the sulphur is eliminated by oxidation at
high temperatures. Off-gases from six fluid bed roasters are cleaned of
particulate materials and sent to the acid plants. These gases can be
temporarily diverted to the 19^ m stack in case of upsets, however, if problems
persist, the plant is shut down. To facilitate the separation of nickel from iron
- la -
in the subsequent leaching and reduction steps and to reduce the oxides of iron,
the concentrate from the roasters is treated in six reduction kilns. Off-gases
from six fluid bed roasters are cleaned of particulate materials and sent to the
19^ m stack. It can be suggested on the basis of stack tests that the reduction
kilns are a major source of particulates emitted from the 19^ m stack. Leaching
and recovery plants are sources of ammonia emissions from small stacks on the
building roof or process equipment vents -ammonia is used in the process of
nickel recovery from the reduced concentrate. The concentrate, removed of
nickel, copper and cobalt, is sent to the iron ore pelletizing plant to produce
concentrate pellets rich in iron and suitable for marketing. In order to produce
the pellets, the leached magnetite from the leaching plant is first dewatered to
make filter cake, which is then dryed in two sintering machines. Gases from
these machines are emitted via two ^5 m stacks and four small stacks on the
building roof. The two t*5 m stacks were major sources of iron and total
particulate emissions in the Basin until the plant shut down in April, 1980.
3.3.2 NICKEL REFINERY
Nickel sulphide from matte processing is further processed in the nickel
refinery to make nickel in either powder or pellet forms. Nickel sulphide,
precious metal intermediate products, and refinery residues are first briquetted
and then oxidized in two converters. The finished metal is further processed to
produce metallic granules which undergo carbonylation, purification,
decomposition and either pelletization or powderization. The most significant
source of emissions to the 194 m stack is the converting step. The gases
exhausted from the converters are passed through electrostatic precipitators
prior to entering the flue leading to the stack. Even though converting is a batch
process operated intermittently, these two converters were the second largest
source of nickel emissions in the Sudbury Basin up until 1980, when additional
precipitation capacity on each converter was installed.
3.3.3 SULPHURIC ACID PLANTS
Inco also operates three sulphuric acid plants, adjacent to the iron ore
recovery process from which they receive sulphur dioxide. The sulphuric acid
process involves oxidation of sulphur dioxide on a catalyst to produce sulphur
trioxide, and absorption of sulphur trioxide in absorption towers. Residual
sulphur dioxide gas not converted to acid (conversion efficiency of about 93%) is
vented to the atmosphere via the 19^ m stack.
3A THE FALCQNBRIDGE 93 M STACK
About 7100 standard cubic meters of gas at 120° - 160°C are emitted from
this stack every minute. The stack receives off-gases from the Falconbridge
smelter operations, which include smelting and converting, as well as the off-
gases from the adjacent sulphuric acid plant. Prior to entering the stack, the
process gases pass through an electrostatic precipitator for the removal of
The Falconbridge smelting process was changed in 1978, hence, the
emissions from the plant should be considered in two periods: before and after
this change. There were no satisfactory emission measurements performed on
the old process and the only acceptable emission estimates up to 1978 are those
of sulphur dioxide as calculated by mass balance. Emissions of some metals
from the old process were also measured on two occasions, however, the
accuracy of these measurements was judged unsatisfactory. Since 1978, two
lines have been instcilled at the smelter, each containing a fluid bed roaster and
an electric furnace, replacing the sintering machines and blast furnaces in the
old process. The off-gases from the roasters are cleaned of particulates in
cyclones and electrostatic precipitators, cooled, and sent to an acid plant for the
conversion of sulphur dioxide to sulphuric acid. The solids from the roasters are
fed to electric furnaces for smelting. Similarly to the roaster off-gases,
emissions from the furnaces are first passed through cyclones and electrostatic
precipitators and then sent to the stack. The furnace matte is sent to converters
for further removal of iron and sulphur. There are four converters of which
three are operated at any one time. The off-gases from the converters are sent
to the electrostatic precipitators and then to the stack.
- 17 -
tt, DISCUSSION OF EMISSION MEASUREMENT METHODS,
THEIR FREQUENCY AND ACCURACY
The emission measurement methods applied at the Sudbury sources varied
in complexity and accuracy, depending on the source and the manpower available
for these measurements. They were, in most cases, either identical to or
modified methods in the Ontario Source Testing Code (OSTC) (36). When
modifications to the prescribed methods were made, it was either demonstrated
that the measurement accuracy was not affected to a large degree or the
construction limitations at the given sources were such that no other acceptable
alternative existed at the time. In some cases, novel and unconventional
methods, such as in-plume measurements, were applied. At most sources,
measurements were done in one period of short duration and, consequently, the
results reflect the emissions in effect during that period.
At the largest Sudbury source, the Inco 381 m stack, the particulate
emission measurements were done at least once a year in the period from 1973
to 1980, producing relatively abundant emission data points. These emission data
were correlated with the emissions of sulphur dioxide, thus enabling prediction of
particulate emissions, within the given error margin, at any time, providing that
either the production rates in the smelter or the emissions of sulphur dioxide
from this stack are known. Emissions of sulphur dioxide from this stack are
measured continuously with a continuous emission monitoring system, however,
in the absence of measured values, these emissions could be calculated by mass
balance. The continuous emission monitoring system at the 381 m stack was
exhaustively examined and calibrated against a reference method in 1973, and it
was then demonstrated that the system was accurate to within 10%.
Me^lsurements of particulate pollutants at the 381 m stack in 1973 and
197^ were done according to rigorous testing procedures, and the obtained
results are believed to be the most accurate of all the emission data available
for this stack. In 197^*, attempts were made to simplify testing procedures and
special tests to compare so called one-point sampling with multi-point sampling
techniques were carried out for the first time. Starting in 1975 only one-point
sampling had been used at this source until 1980, when another simultaneous
single-point and multi-point testing program was performed. These tests were
designed to measure the magnitude of error associated with single-point
sampling. The results suggested that single-point sampling could underestimate
emissions by as much as 60% (22). A similar magnitude of error was indicated
from the correlations between the emissions of particulates and sulphur dioxide
from this stack, as discussed later in this report.
Besides errors arising from single-point sampling, there were
inconsistencies in the chemical treatment of particulate samples in different
years, causing difficulties in comparing the measured yearly values. In order to
remove these difficulties and, at the same time, to conform to the definition of
particulate matter as given in the OSTC, sulphates and free sulphuric acid found
prior to and on the filters of the sampling trains after the tests were considered
particulates and were included in the calculation of particulate emissions. This
still did not eliminate all inconsistencies, particularly those due to different
distribution of acid in the sampling trains caused by different filter temperatures
during samplings, but it helped to obtain better correlations between the yearly
Measurements of sulphuric acid emissions from most of the Sudbury
sources are difficult due to limitations of the sampling method. The method
used in the measurements is known as the U.S. E.P.A. Method 6 (37), which is
directly applicable to sulphuric acid plants, but had to be modified for the other
sources in Sudbury. These modifications were not always successful, and
difficulties were met when trying to separate sulphates from free acid during
sampling and to distinguish between these two species in subsequent chemical
analyses. Selective chemical extractions and elevated temperatures of the
probes and filters of the sampling trains during sampling applied in latter years
helped, but did not completely resolve the problem. In some tests, the solvent
used for the extractions was not completely selective because of impurities, and
the sampling temperatures were not maintained sufficiently high because of
sampling equipment limitations.
Sulphur dioxide is another possible interference in the acid emission
measurements. It can be either oxidized under favourable conditions to form
sulphuric acid or retained in the impinger solutions to interfere in the chemical
analysis. While both of these mechanisms can be controlled by careful
preparation and execution of sampling, it is possible that in the actual
measurements this was not always achieved, and that the sulphuric acid results
from some tests are biased.
Emission measurements of most trace metals were more accurate than
either particulate or acid measurements. Error in these measurements were due
to single-point sampling and the chemical analyses of the samples. The only
exceptions are volatile metcils such as mercury, arsenic, and selenium, which
were determined accurately on one occasion at the 381 m stack by using a
specially designed emission measurement method in 1980.
Emission measurements at the Falconbridge stack and the Inco 19^ m stack
were also difficult due to problems similar to sampling at the 381 m stack:
traversing of stacks and flues was incomplete due to practical limitations and
sarnples of particulates and sulphuric acid were subject to similar interferences.
These problems are fully described in the discussions of emissions of individual
species from these sources.
Mass balance was used to estimate sulphur dioxide emissions, whenever
FKJSsible, and these estimates can be considered accurate to within 10%, as will
be discussed later.
Ammonia emissions from Inco's iron ore recovery plant were estimated by
mass balance, based on measurements related to chemical makeup, liquid
effluent loss, and specific process emission vent losses, with the remaining
unaccounted losses included as part of atmospheric emission loss (24).
The low level emissions from the Inco smelter building as given in the
original testing reports prepared by the company (12, 14, 17, 20, 21) are probably
the least accurate of the emission data presented in this report. This was due to
difficulties in sampling, which are typical in fugitive emission measurements, for
the following reasons: emissions are intermittent in both strength and duration;
sampling areas are large, with uneven gas flow and occassionally low gas
velocities; problems are experienced in locating "representative sampling
points*'; there are difficulties in assigning a portion of unconfined and wandering
emissions to a specific process unit within the building; and, commercially
available sampling equipment is not suitable for these measurements and special
sampling trains have to be built. Low level emission measurements at Inco's
smelter were done on a process unit basis, where a reverberatory furnace, a
nickel converter, a multiple hearth roaster, the copper flash furnace and a
copper converter were selected as representative of other corresponding process
units in the building, and the measured emissions prorated to include all process
- 21 -
units. Measurement errors eissociated with individual process units are given in
the testing reports and they were used to calculate the total error in the
reported low level sulphur dioxide emissions from the smelter. This error was
+27% (33). The error in particulate emissions was not estimated, but it is
expected to be larger than in the case of sulphur dioxide because of possible
stratification effects on sampling accuracy.
The size of emitted particulates from the stacks was measured by
impaction techniques and generally these measurements are considered accurate.
When there were doubts about the execution of some tests, the tests were
repeated and unreliable results discarded.
In-plume measurements were also attempted as a substitute for in-stack
emission measurements. Sometimes the results from the two methods were
fairly similar, however, on occasion the differences were large and impossible to
explain. In these cases it was assumed that the in-stack method was more
5. SULPHUR DIOXIDE EMISSIONS
Yearly sulphur dioxide emissions from most smelting processes could be
conveniently calculated by a mass balance procedure. However, difficulties and
inaccuracies could arise, if the emission data from more than one stack which
receive off-gases from the same process are required. In these situations,
sulphur dioxide measurements at each stack is the only viable alternative.
Measurements will also produce more accurate emissions over shorter periods,
e.g. days or weeks, when inaccuracies in process sampling and weighing of the
process streams required for mass balance could have a more significant effect
on the accuracy of emission calculations.
A combination of measurements and mass balance was used to produce
sulphur dioxide emissions from the major industrial sources in the Sudbury Basin
as shown in Tables 1 and 2. Emissions from the Inco 381 m stack are mass
balance values as reported by the company and they agree with the yearly
average of the measured values to within 1-2%. Since the measured values were
shown to be accurate to within 10% (1), it is likely that the mass balance values
in Table 2 are at least as accurate. As far as other emissions in Table 2 are
concerned, the Falconbridge and Inco 19^ m stack data were obtained by mass
balance, while the Inco smelter low level emissions were measured in 1978 and
1979, and prorated to other years on the basis of production.
For Inco, shutdowns and/or labour strikes in 1978 and 1979 were responsible
for lower emissions in the Basin in those years. Sulphur dioxide emissions for
1980 and 1981 from the Inco 381 m stack reflect more stringent emission
requirements imposed by the Ministry in 1980 which were met as a result of
reduced production. With respect to emissions from the Falconbridge smelter,
the levels were reduced as of 1978 largely due to process changes (installation of
fluid bed roasting - electric furnace smelting - sulphuric acid manufacturing).
However, summer vacation shutdowns and lower production levels also
contributed to the lower emissions presented in Table 2. In other respects, the
tabulated emissions should be regarded as representative of each source. The
measurement methods, correspondence between emissions and production as well
as the accuracy of prorated emissions given in Table 2 are discussed for each
TABLE 2: YEARLY EMISSIONS OF SULPHUR DIOXIDE FROM MAJOR
INDUSTRIAL SOURCES IN THE SUDBURY BASIN IN THOUSAND TONNES
Inco 381 m
Inco Low Level
Inco 194 m
96 of total
Determined by mass balance Ccilculations
** Determined from measurements in 1978 and 1979 and prorated to other
years on the basis of production,
*** Determined from stack measurements.
5.1 THE INCO 381 M STACK
With 7896 contribution to the total emissions of sulphur dioxide in the
Sudbury Basin, the 381 m stack is the largest single emitter of sulphur dioxide in
the area. The accuracy of total sulphur dioxide emissions from the Basin
depends to a large extent on the accuracy of these 381 m stack emissions, and it
is for this reason that they have been measured on a continuous basis since 1973,
" T i S i i i I * ^ ^ ^ ^ *■ ^ * ^
B B P ■ i i B R n r B B P ■ R n
E5TIMRTED 5D2 EM 1 55 1 DN BY MR55 BHLRNCE ( TDNNE5/H )
FIGURE 2. SULPHUR DIDXIDE EM1551DN5 CDMPUTED BY MR55 BRLRNCE
V5 EM 1 55 I DNS MER5URED RT THE INCD 3B I M 5TRCK
The continuous emission monitoring installation for sulphur dioxide was verified
through extensive testing in 1973, when it was demonstrated that the system was
accurate to within + \0%. The measured emissions were also compared with the
available computational estimates by mass balance in 1973 and 197^, and a
relationship between these two sets of results is shown in Figure 2,
The plotted line in Figure 2 represents an ideal one-to-one relationship,
assuming no error by either method. The measured values are spread around this
line with the largest individual point deviation being about 30%, which,
considering that both the continuous monitoring and short term mass balance
methods are susceptible to errors, should not be unexpected. Figure 2 still
illustrates that the two methods are essentially equivalent over longer time
periods. This equivalency has also been confirmed in Inco's progress reports on
continuous monitoring, which indicate that yearly values obtained by the two
methods agree to within 2%, while monthly averages may differ by as much as
The available measured emissions were also plotted against the total ore
concentrate input to the roasters and the total feed to the nickel converters in
Figures 3 and ^, respectively. Straight best fit lines shown in these figures were
calculated by the least squares method.
The large scatter of points about the lines in Figures 3 and ^ may be a
result of the variable sulphur content of the feeds to both the roasting and
converting operations. More uniform sulphur content of the reverb matte fed to
the converters resulted in better correlation and smaller scatter in Figure ^,
From these figures, it is calculated that, depending on feed rate, sulphur dioxide
emissions range from 0.66 to 0,78 tonnes for every tonne of the total material
input into the converters and from 0.61 to 0.8^ tonnes for every tonne of the ore
concentrate fed into the roasters.
RDH5TER MRTERIflL INPUT ( TDNNE5/H )
SULPHUR DIDXIDE EMI5S1DN5 V5 RDR5TER MRTERIRL INPUT
1 i 1 f
CDNVERTER MBTTE INPUT ( TDNNE5/H )
FIGURE H. SULPHUR DIDXiDE EMISBIDNB V5 CONVERTER MRTTE INPUT
The significance of the relationships between the process material flows
and sulphur dioxide emissions is that they illustrate a proportionality between
these two parameters and enable use of either of them as an indicator of
production activity in the smelter. However, a caution should be exercised
because the correlations as calculated from Figures 3 and ^ may have changed
since 1973, as a result of process changes, but these changes are not expected to
alter the fact that the sulphur dioxide emissions are directly proportional to
5.2 INCQ LOW LEVEL EMISSIONS
The low level emissions from the Copper Cliff smelter building were
measured by Inco personnel in a series of tests at various vents, windows, and
small stacks on the roof of the building. No similar measurements were done at
the other Inco buildings or the Falconbridge smelter. The tests at Inco were
specially designed and executed such that the measured emissions from the
single process units selected for measurements as representative of a number of
similar units in the same building were used to calculate the total emissions from
the building. The origin of these emissions was already discussed in general
terms in the process description; however, for more details, reference should be
made to the relevant Inco reports (12, 14, 17, 20, 21). Emissions shown in Table
2 were prorated to average yearly production rates of bessemer matte and
blister copper. Difficulties encountered in these measurements as well as some
estimates of associated measurement errors are given in the Inco reports listed
above. From these error estimates, it was calculated that the total low level
emissions of sulphur dioxide shown in Tables 1 and 2 should be accurate to
within + 27% (33).
From among the individual processes, the largest contributor to these low
level emissions of sulphur dioxide are the reverberatory furnaces which account
for about ^2% of the total low level sulphur dioxide emissions, followed by the
converters at 38%, the copper flash furnace at 19% and the roasters at 1% (21).
From another Inco report (27), the contributions to the total emissions for the
copper converters are ^1%, followed by the nickel reverberatory furnaces at
25%, the copper flash furnace at 17%, the nickel converters at 8% and
miscellaneous sources at 9%,
5.3 THE INCO 19^ METRE STACK
The flues from Inco's nickel refinery, the sulphur products plant and the
iron ore recovery plant are joined to the 19^ m stack. Because of the
unavailability of suitable sampling platforms at the stack, all emission
measurements were carried out at the three flues that convey the emissions
from the individual plants to the stack. Sulphur dioxide emissions and the
corresponding production rates, as given in the emission testing reports (8, 9, iO),
are shown in Table 3.
Sulphur dioxide emissions in Table 3 are based on the results of several
tests of limited duration carried out when the production rates were as
indicated. Only in the case of the nickel refinery were the emissions prorated to
correspond to a typical production rate in 1977. These nickel refinery emissions
are intermittent, and the result in Table 3 corresponds to approximately three
"converter heats" per day, each heat lasting about four and a half hours. The
emissions during the heat changed from a low of 5% to a high of 60% of the total
for the heat. Emissions from the sulphuric acid plant are continuous and also
dependent on production. The sulphuric acid production rate shown in Table 3 is
somewhat less than the maximum rated capacity of 2721 tonnes per day.
Emissions from the iron ore recovery plant are continuous and subject to
fluctuations. The fluctuations were so large during testing that some doubts
about the validity of tests and the meaning of the obtained results were
expressed (29). Fortunately, this plant is the least significant contributor of
sulphur dioxide emissions to the 19^ m stack, and any error in these
measurements will not affect significantly the accuracy of the total emissions
from the stack.
All emissions from individual flues were measured instrumentally, and in
the case of the nickel refinery, they were compared with mass balances
calculated over both short and long time periods (9). The agreement between the
measurements and long-period calculation was excellent, while short period mass
balance indicated about 62% lower emissions.
TABLE 3: SULPHUR DIOXIDE EMISSIONS FROM INDIVIDUAL PROCESSES
TO THE INCO 19^!^ METRE STACK IN TONNES/DAY IN 1977.
Sulphuric Acid Plants
Nickel Refinery Plant
Iron Ore Recovery Plant
2300 tonnes/day of
21^.2 tonnes/ day of
dry charge to refinery
2267 tonnes/day of
- 31 -
5A THE FALCQNBRIDGE 93 M STACK
This stack is the second largest sulphur dioxide emitter in the Sudbury
Basin, contributing on average about 16% of the total over the nine year period,
as indicated in Table 2. These emissions have been computed by mass balance
and reported by the company (13). In 1979, they were also measured over a short
period, and the measured emissions were compared with the meiss balance values.
The comparison was not successful in that the measurements indicated about
^9% higher emissions, probably as a result of errors in both the measurement and
short term mass balance. However, the values in Table 3 should still be
considered as an accurate representation of the emissions from this stack. The
Falconbridge plant emissions are variable due to a batchwise operation of the
converters and possibly variable efficiencies of the sulphuric acid plant, which
both release off-gases to the 93 m stack.
6. EMISSIONS AND SIZE OF TOTAL PARTICULATES
Total particulates are the second most significant pollutant emitted from
the industrial sources in the Sudbury Basin. However, in comparison to sulphur
dioxide, the particulate emissions amount to only about 1.8% of the sulphur
Similarly to sulphur dioxide, most of the particulate emissions in the basin
are due to Inco's 381 m stack. The 381 stack emissions, as shown in Tables 1 and
i^t were obtained from a linear correlation between the particulate and sulphur
dioxide emissions measured in the period from 1973 to 1980 such that they
correspond to yearly emissions of sulphur dioxide. Since the sulphur dioxide
emissions depend on the production rates in the smelter, the estimated
particulate emissions are indirectly normalized with respect to production and
represent the best available average particulate emissions from this source.
Since about 75% of the total particulate emissions in the Sudbury Basin are due
to the 381 m stack, any variation in these emissions will have a significant effect
on the overall emissions of total particulates as well as of the other particulate
pollutants in the Basin.
The low level particulate emissions as shown in Table fi- were also
normalized with respect to production; however, in this case only one set of
measured values from Inco's 1978-1979 testing program was available.
Consequently, the calculated emissions shown in the table are less accurate then
those for the 381 m stack. No such normalization was done for any other source
listed in Table 4, and the indicated emissions from these sources were measured
in only one set of tests. Emissions from the two ^^5 m smokestacks ceased in
April 1980, when the pellet plant was shut down (25). Emissions from the Inco
19^ m stack have also been reduced since 1980, when additional precipitators
were installed at the nickel refinery flues. Presently, no satisfactory stack test
data are available for the estimation of this reduction.
TABLE ^: YEARLY EMISSIONS OF TOTAL PARTICULATES IN TONNES
FROM MAJOR SOURCES IN THE SUDBURY BASIN
FROM 1973 TO 1981.
Inco 381 m
Inco Smelter Low
Inco 194 m
and two 45 m
* Emissions from two 45 m stacks not applicable after April 1980, due to
** These emissions were decreased in 1980 as a result of additional
precipitator capacity at the nickel refinery plant flues.
6.1 THE INCO 381 M STACK
Emissions of total particulates from the 381 m stack were measured in at
least one short period every year from 1973 - 1980, The average results of these
measurements are shown in Table 5. They were based on: one test in 1975, two
tests in each of 1976, 1978, and 1980, four tests in each of 1974 and 1977, six
tests in 1973 and 16 tests in 1979. Other tests that could have been done in any
of these years were excluded because of a lack of detailed data on the chemical
composition of the samples. Since the number of tests, the time periods of
testing, and the production rates differed in each of these years, the emissions in
Table 5 cannot be compared directly with each other or considered as
representative of yearly emissions. Also, they are not identical to the emissions
given in the original test reports because of the inclusion of the condensed acid
in the particulate emissions. This inclusion was done to enable a direct
comparison of emissions measured in different years and to conform with the
definitions in the provincial testing code. In earlier reports, the original
emissions included the part of sulphuric acid which was condensed at the
sampling temperatures while the particulate emissions in later reports were
completely free of this acid (different chemical treatments of particulate
samples in different years were responsible for these inconsistencies). In the
1973 and 197^ tests, particulate samples were extracted with acetone which
removed some of the acid, and these partially acid-free particulates were used
to calculate the particulate emissions. Starting in 1975, isopropanol replaced
acetone because of its effectiveness as a selective extractive chemical for the
free acid and, consequently, the emissions after 1975 did not contain any free
sulphuric acid. In order to make all emissions measured at this stack
comparable, the condensed acid, which at the sampling temperatures had been
collected as a particulate, was included in the particulate emissions. In doing so,
these emissions also conformed with the definition of particulates given in the
provincial testing code (OSTC). Additional benefit was a slightly better
predictability of particulate emissions from the knowledge of production and
emissions of sulphur dioxide.
The individual particulate emission results which were used to obtain the
average emissions shown in Table 5 and the sulphur dioxide emissions measured
simultaneously with the corresponding particulate tests were plotted and are
shown along with a best-fit line in Figure 5. A plot of associated frequency
distribution of errors in tonnes per hour is shown in Figure 6.
TABLE 5: MEASURED AVERAGE PARTICULATE EMISSIONS FROM THE
INCO 381 m STACK IN TONNES/HOUR
in Tonnes/ h
The broken lines in Figure 5 indicate the limits in the standard error of
estimate associated with the prediction of particulate emissions from this
straight line relationship. Figure 6 illustrates that the points are scattered
around the straight line in a random fashion, suggesting normal distribution of
errors. These errors are compounded and consist of measurement errors and
random process variations which could cause different relationships between the
emissions of these two pollutants. Measurement errors alone could account for
as much as 7^^ of the total error of which 10% could be due to sulphur dioxide
determination and 6096 to particulate measurements, as discussed earlier.
Despite the errors, or large scatter of individual measurements in Figure 5,
this straight-line relationship can be used to either estimate particulate
emissions from the knowledge of sulphur dioxide emissions or to assess the
process operation when emissions of both pollutants are known. In case the two
emissions fall outside the area enclosed by the broken lines in Figure 5, a
significant change in the process operation could be suspected.
Some of the emission data used in calculating the straight-line relationship
in Figure 5 were obtained shortly after improvements to the electrostatic
precipitators had been made, hence, the effects of these improvements on the
particulate emissions are included in the relationship (31). These effects are also
responsible for the largeness of scatter in Figure 5. In an attempt to further
explain this scatter, residuals (difference between the measured and predicted
value) from Figure 5 were plotted against years. This plot suggested that a
significant drop in emissions may have occurred in 1976; and since the emissions
were already normalized for production, this drop could not have resulted from
lower production activities in the smelter. Since 1976 the normalized emissions
have been steadily increasing until 1980, when they may have been only about
10-20% lower then in 1973.
The straight line relationship in Figure 5 was used to calculate the annual
emissions of particulates in the period from 1973 to 1981 from the knowledge of
the annual sulphur dioxide emissions (3^*). In Table 4, the calculated annual
particulate emissions and the standard error of estimate are given. The
calculated emissions are different from the measurement averages shown in
Table 5 because of differences between the production rates during tests and the
annual production rates. As a result, the calculated average emissions over the
eight year period from 1973 to 1980 are smaller and amount to only about 83% of
the average measured values in the same eight year period.
6.2 THE INCQ 194 M STACK
This stack is the second largest industrial source of particulate emissions in
the Basin. From among the three groups of plants contributing to
E(PRRTI<:ULRTE) ^ E(BD2) X 0.0103 + 0.2907
CDRRELRTIDN COEFFICIENT = 0.S3
5TBNDHRD ERROR DP ESTiMRTE (5X/Y ) +
= ± . 5:237
5D2 EM IBS I DN ( TDNNE5/H )
FIGURE S. TQTRL PRRTKULRTE V5 SULPHUR DIDXIDE EM I 5B 1 DN5
5Nai55m3 3<]ixai<] ynHdins ba
3iBin:>iiyHd bua smahi jd NDiinaiyisK] A3N3nH3yj
ZQ5 5A 'Lm6
the emissions from this stack, the acid plants are the least significant
contributors of particulates, accounting for about 8% of the total emissions,
followed by the nickel refinery with 36% and the I.O.R.P. with 56%. The
average particulate emissions as measured in 1976, the corresponding production
rates, and the particulate emission factors are shown in Table 6.
Comments on the continuity of emissions from the iron ore recovery plant
(I.O.R.P.) and the three acid plants, their intermittency from the nickel refinery
plant, and on the production in the plants given in the discussion of sulphur
dioxide emissions are also applicable to emissions of particulates. The nickel
refinery is an intermittent source and its daily emissions as shown in Table 5
cannot be divided by 2^ to obtain the actual hourly emissions since the hourly
emissions fluctuate depending on number of heats performed in the day and heat
cycle. The emissions in Table 5 represent the total from three heats a day, each
heat of four and a half hours duration.
TABLE 6: PARTICULATE EMISSIONS FROM THE INCO 19^ M
STACK IN TONNES/DAY
Sulphuric Acid Plants
2308 tonnes* */day
1.5 kg/ tonne
* Tonnes of sulphuric acid
** Tonnes of pyrrhotite
* ** Heats of converters
o Particulate Emissions/Production
* Emissions applicable up to 1980.
installed in 1980.
More electrostatic precipitators
As far as the accuracy of measurements are concerned, problems were
experienced in sampling at both the I.O.R.P. and the nickel refinery plant due to
nonideal measurement locations and partial traversing within the horizontal
flues. Consequently, the particulate samples collected in these measurements
may not be representative of the particulates emitted from these plants. No
specific tests were performed at either plant to provide the data required for the
estimation of measurement errors, however, these errors could be expected to be
larger than the 60% estimated for the 381 m stack.
Particulate emissions from the nickel refinery plant were decreased in
1980 after the installation of additional precipitators in the two converter flues
(30). However, no satisfactory emission testing data are presently available to
either assess the degree of improvement or to quantify the emissions of
particulate pollutants from the new process.
The acid plant emissions in Table 6 include the portion of sulphuric acid
which was condensed at the sampling tempjerature, in accordance with the
discussion of particulate emissions from the 381 m stack. No such corrections
were applied to the emissions from the other two plants because the data on the
condensed portion of the acid was not available..
6,3 THE FALCONBRIDGE 93 M STACK
Particulate emissions from the 93 m stack were measured in 1973 and
1979. The results from 1973 are the only available emission data applicable to
the old process at the Falconbridge plant and they suggest fairly high emissions
at 19,2 tonnes per day. Unfortunately, since these measurements were done at
only one point of the stack cross-section cind were short in duration, their
accuracy cannot be considered satisfactory.
- 1*1 -
A more detailed measurement program was executed in 1979, when the
new process was on line. The measured emissions were much lower at 2.37
tonnes per day. The error associated with these measurements was estimated at
about + 38%. These emissions were recalculated to include the condensed
portion of sulphuric acid.
During the emission measurements, the average feed rate to the roasters
was equivalent to 1,703 tonnes per day. The particulate emission factor based
on this roaster feed is 1,^ kg of particulates for each tonne of the roaster feed.
G.it INCO'S LOW LEVEL EMISSIONS
The relative contribution of this source to the total particulate emissions
from the Basin is surprisingly larger than in the case of sulphur dioxide
emissions. The low level particulate emissions at 1.6 tonnes per day account for
about 3.9% of the total particulate emissions in the Basin, while a similar
percentage for sulphur dioxide is about 1.1%. It is not known whether this is a
result of measurement errors or a reflection of the actual relationship between
these two pollutants in low level emissions. As was already indicated in the
description of processes and measurement methods, the measurement of low
level emissions was a difficult and complex task, which required development of
special methods. These methods were at times crude and unproven. For
example, in one case, visual observation was used to assign a relative
contribution factor to the emissions sampled in a ventilator for each of the two
adjacent process units. This factor was then used to calculate emissions from
similar units. In other instances, particulate emissions were sampled in large
ventilators over long time periods, using methods which had to be simplified in
order to make them practical. While these simplications may have a less
significant effect on the accuracy of measurements of gaseous species, e.g.
sulphur dioxide, they could cause larger errors in the case of particulates.
Hence, it should not be surprising if the measurement error in some tests was
even greater than + 60% as reported by the Inco's smelter process technology
From among individual smelting processes, the largest contributor to the
low level particulate emissions from the smelter are the copper converters,
accounting for 6^-70% of the total, followed by the multiple hearth roasters with
9-11%, the reverberatory furnaces with 9-11%, the nickel converters with 9-11%
and the copper flash furnace with 3% (21,27). Emissions from each of these
processes were prorated to include production in all units in the smelter and so
prorated emissions are shown in Tcible 4 (38).
6.5 SIZE OF EMITTED PARTICULATES
Emissions from all processes in consideration are cleaned from a bulk of
pollutants, particularly those in particulate form, prior to entering the stacks.
Electrostatic precipitators are used in the majority of the plants, except at the
sulphuric acid plants where water scrubbers are used. These precipitators are
particularly effective in removing particulates of large size, thereby leaving in
the emissions mostly particulates with aerodynamic diameters of less than 10 to
15 urn. These small particulates could be airborne and respirable, and, therefore,
it is important to characterize them in terms of size and chemical composition.
Commonly used parameters in particle size characterization are the
aerodynamic diameters (DP) of the given weight fractions of the particulate
sample. Thus DP 50% of 5 um means that, in terms of weight, 50% of all
emitted particles have aerodynamic diameters equal to or less than 5 urn. In
addition to DP 50% or mass median diameter (MMD), cut-off diameters of 15.9%
and 84.1% weight fractions of the sample are usually reported, to enable a more
complete characterization of the size distribution, Impactor methods, which are
frequently used in the size measurements, do not always distinguish between
particles larger than about 10 to 15 urn. In order to obtain the size information
in this range, the measured data must be extrapolated, which in turn may
accentuate small measurement errors to quite large differences in the
extrapolated results. This source of error must be recognized when interpreting
the sizing data.
Particulate sizes were measured at the Inco 381 m stack on several
occasions and at the Falconbridge's 93 m stack once. No measurements were
performed at the other sources. Both in-stack and in-plume measurements were
carried out at both of these stacks.
6.5.1 PARTICULATE SIZE MEASUREMENTS AT THE INCO 381 M STACK
The in-stack particulate size measurements at the 381 m stack were done
over the period of eight years, and the results of these measurements are given
in Table 7.
The available test data from 1973 do not contain the weights of large particles
retained in the inlet portions of the impactor samplers, resulting in too small
mass median diameters, as shown in Table 7. However, if the data from 1976 are
truncated to exclude the inlet portions of the samples, the mass median
TABLE 7: SUMMARY OF PARTICLE SIZE MEASUREMENTS AT
THE INCO 381 M STACK
No of Tests
% of Sample
6.8 - 7 A
0.9 - 1.3
16 - 1*7
3.5 - 5.5
0.65 - 0.89
19 - 36
3.3 - G.ii
0.53 - 0.72
23 - 60
* Incomplete sample yielding a nonrepresentative result.
diameters of the truncated samples are comparable to those from the 1973
program. This suggests that the size of particulates in 1973 and 1976 may have
been similar. The particulate size distributions in 1976 and 1977 were also
similar. Tests in 1978 and 1980 resulted in slightly smaller particulates.
Measurements in 1978 were particularly exhaustive, and the results from that
year can be considered accurate and representative of emissions from this stack
6.5.2 PARTICULATE SIZE MEASUREMENT AT THE FALCONBRIDGE 93 M STACK
The size measurement tests at this source were performed in 1979, and the
particulates were found to be somewhat smaller than in the Inco 381 m stack.
Since similar measurement methods were used at both sources, the differences in
the results must be attributed to processes and process equipment, including the
electrostatic precipitators at the two smelters. The results obtained at the
Falconbridge stack are given in Table 8.
- ii^ -
TABLE 8: SIZE OF PARTICULATES EMITTED FROM
THE FALCONBRIDGE 93 M STACK
No of Tests
OAH - 0.66
% of Sample
In-plume measurements were also carried out at Faiconbridge, and no
significant diftcrences between the in-plume and in-stack size measurement
results for most metals of interest were recorded (19, 23).
7. EMISSIONS OF METALS
Emissions of metals in the Sudbury Basin follow the trend established for
particulates, thus, on the average the largest source of nickel, lead and arsenic
emissions is the Inco 381 m stack, followed by the Inco 19^ m stack, the
Falconbridge 93 m stack, and Inco's Copper Cliff smelter building. However, in
terms of particulate composition, the 194 m stack is by far the most significant
source of copper and nickel. Even in terms of absolute quantities, this source
used to emit almost as much of these two metals as the 381 m stack prior to
installation of additional precipitation capacity at the nickel refinery in 1980.
(No satisfactory emission data applicable to the present operation at the refinery
are available). Another significant source of copper is Inco's Copper Cliff
smelter building, contributing about 37% of all copper emissions in the Basin.
Iron was mainly emitted from Inco's two 45 m stacks until the pellet plant
shutdown in 1980.
Not all metals were determined in all emission measurements for the
Sudbury sources, however, the major species which, on the average, exceeded
both one percent content of total particulate and the emission rate of 10 kg/h
from the 381 m stack over the eight year period from 1973 to 1980, were
quantified at all sources, and their emissions are listed in Table 9.
The iron, copF)er, and nickel emissions from the 381 m stack were calculated
from correlations with sulphur dioxide, while lead and arsenic emissions were
averaged from three or more valid emission measurement tests. Emissions of
metals other than those in Table 9, including cobalt, selenium, mercury,
chromium, manganese etc., accounted for less than 1% of particulate emissions,
as discussed under individual sources.
TABLE 9: AVERAGE EMISSIONS OF METALS FROM MAJOR
SUDBURY SOURCES IN KILOGRAMS/HOUR
Inco 3Si m
Inco 19'» m
Falconbridge 93 m
Inco two i^i m
Sx,y = standard error of estimate
(T = standard deviation
Emissions measured in 1977, inapplicable after the installation of new electrostatic
precipitators at the nickel refinery in 1980.
Emissions inapplicable after the pellet plant shutdown in 1980. Excluded from the total.
Metals were analysed in almost every sample collected in the course of
particulate emission measurements at all Sudbury sources- Analyses were
frequently performed by at least two laboratories, Falconbridge's or Inco's and
the Ministry of the Environment's. In the first sampling campaign at the 381 m
stack, a third independent laboratory was engaged to analyse selected samples
for cross-checking purposes. This was justified on the basis of uncertainties and
novelties involved in early analytical work; however, when the proper procedures
were well established and the approximate levels of metals in the emissions
became known, the number of laboratories involved in any given measurement
program was decreased. The number of metals analysed in particulate samples
was also decreased to include only major constituents.
Some metals of interest, mercury, arsenic, lead and selenium, are volatile
and their collection in the sampling stage was not always assured. Thus, if the
particulate sample was analysed for any of these four species with no
modification in the sampling procedure to ensure their quantitative collection,
the obtained results were in error and inconsistent with expectations. In the
case of the 381 m stack, these uncertainties were removed by performing
specially designed emission tests in 1980, and this program resulted in the most
reliable emission data for these metcils from this source.
The metal emissions from the 381 m stack depend on production and
increase proportionately with the sulphur dioxide emissions. This dependence
and a relative abundance of pertinent data enabled development of correlations,
which were then used to estimate annual emissions of copper, nickel, and iron
from the 381 m stack. An insufficient number of tests at other Sudbury sources
was the reason that no similar correlations for those sources were produced,
7.1 THE INCO 381 M STACK
The best estimates of average hourly emissions of major metals from the
381 m smokestack in the period from 1973 to 1980 are shown in Table 10.
The iron, copper, and nickel emissions shown in this Table were calculated on the
basis of yearly sulphur dioxide emissions from straight line correlations between
the measured emissions of each metal and sulphur dioxide (the measured
emissions of these metals are shown in Table 11). The straight lines with the
limits of standard errors of estimates and the associated frequency distribution
of errors graphs are shown in Figures 7 through 12.
TABLE 10: AVERAGE EMISSIONS OF FIVE MAJOR
METALS FROM THE INCO 381 M STACK
•Emissions calculated from regression lines
The straight-line correlations were selected after several linear and
nonlinear functions were examined for the goodness of fit through the measured
data points plotted on graphs. Among the linear functions, polynomials of up to
fifth order were studied. In comparison to the straight lines, the polynomials of
higher order were either very similar to the straight lines or unsuitable in that
they overfit the data points. Among the nonlinear functions, the exponential
correlations resulted in improved correlation coefficients, but also in poorer
distribution of errors than the straight-line correlations. The average emissions
of the three metals calculated from the exponential correlations over the eight
years from 1973 to 1980 were lower than the corresponding emissions calculated
from either the straight lines or the average measured values. However, when
the errors ot estimates were taken into account, no significant difference in the
values estimated from either function could be found. In this situation a choice
of the mathematically simpler straight lines was justified. The estimates of
emissions from the straight-line correlations as shown in Table 10 are more
representative of the actual emissions than the mathematical averages of
measured emissions shown in Table 1 1 because they were normalized with
respect to the production rates.
The scatter of individual data points about the lines in Figures 7, 9 and 1 1
is admittedly large, but also understandable in the light of variations in
particulate composition, process operation, sulphur dioxide emissions, and the
measurement errors which could all contribute to its magnitude. Errors are
associated with the estimates from these lines and they must be taken into
account when interpreting the calculated emissions. Distribution of errors of
estimates about these straight lines seem skewed, suggesting that a lognormal
analysis could be appropriate. It must be also ensured that no significant
changes in the process have taken place, if the emissions beyond 1980 are
calculated from these straight lines. Better correlations with less scatter were
obtained in the case of metals versus particulates, indicating consistency in the
chemical analyses of the emission samples.
Attempts to correlate arsenic and lead emissions with sulphur dioxide were
unsuccessful in that their emissions were inversely proportional. One of the
possible reasons for this unexpected result is nonquantitative collection of these
species during particulate emission measurements. A special sampling method
for arsenic, selenium and mercury was employed in the 1980 sampling program,
but the results did not indicate large differences from the past programs.
Measured average emissions of all species in particulate form, including
metals, are shown in Table 11.
In-plume measurements of metal emissions *'om the 381 m stack were
performed simultaneously with the in-stack measurements in 1977 (11, 15). The
results from these tests were comparable, except for arsenic with higher
emissions measured in a colder plume. A similar comparison attempted in 1980
resulted in larger discrepancies, with the in-plume method yielding several times
E(FE) = E(5D2) X 0.00IG5 - 0.0HBa3
CnRRELRTIQN CDEFFICIENT = a.H3
bTHNDRRD ZRKUii DP ESTiMfiTE CSX/Y 5
= * li: . 1 ZBE
5D2 EM 1 55 1 DN ( TDNNES/H )
figure: 7. IRDN V5 5UL.PHUR DIDXIDE: EMi55mN5
\ FE V5 snz
1 * — W7n — ■ —
— 1 • • ■ I ■ 1 — - -1
B B i i ■ B B B
M 5 f -• •- a «- H
Cn.L LIMITS xia"^
' D 5TR BUT DN DF ERRDR5
FDR RON V5
5ULPHUR DIDXIDE EMISBIDNS
Eccu) - E(5n2) X H.iaiaaiE - la.iaiaBia
CDRRELRTIDN CDEFFICIENT - 0.SB
STRNDHkl: EhKDH Df EbTiMfiTE C^X/Y )
5D2 EM I SB I DN ( TDNNE5/H )
FIGURE g. CDPPER V5 SULPHUR DIDXIDE EM 155 1 DNS
CU V5 5D2
COL LIHITS XII
FIGURE 10. FREQUENCY D15TRIBUTIDN DF ERRDR5 FDR CDPPER V5
SULPHUR DIDXIDE EMI 55 1 DNS
E(N1) - E(5a2) X 0.00037 - 0.01009
CORRELRTIQN CDEFFKIENT = 0.SB
STRWDRRD ERROR DF ESTiHRTE (5x/Y )
i ■ •
B R n f
9 H B P B n
5D2 EMISSION ( TDNNES/H )
. NICKEL. V5 SULPHUR DIUXIDE EMIBBIDNB
Nl V5 5D2
COL UNITS XII
FREQUENCY DISTRIBUTION DF ERRURS FDR NICKEL V5
SULPHUR DIDXIDE EMI55IDN5
TABLE 11: AVERAGE MEASURED EMISSIONS OF METALS AND OTHER PARTICULATE
POLLUTANTS FROM THE INCO 381 M STACK IN KILOGRAMS/HOUR
Emission rates of mercury were measured in 1980 at 7 grams per hour.
TABLE 11 (CONTINUED): AVERAGE MEASURED EMISSIONS OF METALS AND OTHER
PARTICULATE POLLUTANTS FROM THE INCO 381 M STACK IN KILOGRAMS/HOUR
TABLE 11 (CONTINUED): AVERAGE MEASURED EMISSIONS OF METALS AND OTHER
PARTICULATE POLLUTANTS FROM THE INCO 381 M STACK IN KILOGRAMS/HOUR
- 58 -
lower emissions for most metals. Arsenic was again an exception, with much
higher emissions measured by the in-plume method.
From among the five major metals, iron, copper, and nickel tend to be
emitted in larger sizes, with mass medium diameters of more than 13 um, while
the more volatile lead and arsenic are much smaller in size, with MMDs of about
1 um (35).
7.2 THE INCO 194 M STACK
The iron ore recovery plant and the nickel refinery are the only plants
contributing metals to the 194 m stack emissions (the acid plant emissions are
essentially metal-free). The combined emissions of iron, nickel and copper from
these two processes are as large as those from the 381 m stack. Iron is
largely emitted from the iron ore recovery plant, while copper and nickel are
mostly contained in the nickel refinery emissions. In-stack emission
measurements at all plants - iron ore recovery, nickel refinery and sulphuric acid
plants - were performed only on one occasion in 1976, consequently, no
dependence of emissions on production can be illustrated. Rather, the
production rates during the measurements, as shown in the relevant Inco reports
(9, 10), will be given. In addition to these in-stack measurements from 1976,
there are 1979 in-plume emission data available for comparison of the two
methods; this is illustrated in Table 12 (28).
As will be discussed later, the in-stack measurements were not performed
according to strict testing procedures, and the results could be in error. In the
case of copper and nickel they are probably too low. The in-stack and the in-
plume measurements were not conducted simultaneously, but since the two
processes were operated at similar production rates during these measurements,
TABLE 12: COMPARISON OF IN-STACK AND IN-PLUME
AVERAGE EMISSIONS IN TONNES/DAY
the emissions obtained by the two methods can be compared. As already
discussed, the in-plume method produced relatively lower emissions of iron,
copper and nickel, and higher emissions of arsenic.
Emissions of metals (in-stack measurements) from the iron ore recovery
and nickel refinery plants are shown in Table 13. Emissions from the iron ore
recovery plant are continuous, and the corresponding values Irom Table 13 can
be prorated to any time period. As far as representativeness of emissions is
concerned, similar comments to those made in the discussion of particulate
emissions from this plant apply. The sampling method employed in the emission
measurements was not rigorous enough to ensure collection of representative
samples and large errors in the emissions as shown in Table 13 are possible.
The emissions from the nickel refinery may also be in error and are
probably too low. These emissions are not continuous; they originate in nickel
converting, which is a batch process. In calculating the emissions in Table 13, it
was assumed that 3.06 batches of 70 tonnes of charge, each of ^.5 hours
duration, were processed in a day. In order to obtain approximate actual
TABLE 13: EMISSIONS OF METALS FROM THE IRON ORE RECOVERY
AND NICKEL REFINERY PLANTS IN KILOGRAMS/DAY
TABLE 13 (CONTINUED): EMISSIONS OF METALS FROM THE IRON ORE
RECOVERY AND NICKEL REFINERY PLANTS IN KILOGRAMS/DAY
emissions per batch, the emissions in Table 13 must be divided by 3.06. Metal
emissions are not uniform throughout the batch and they change in each of the
three cycles - charging, blowing and reduction. In comparison to nonvolatile
metals such as iron, copper, and nickel, which are mostly emitted during
charging and blowing, half of the more volatile lead and arsenic are emitted
7.3 LOW LEVEL EMISSIONS FROM THE INCO SMELTER BUILDING
Except for copper, which is emitted in considerable quantities in
unconfined or fugitive emissions from the copper converters, the low level
emissions from the Inco smelter building are relatively small contributors to the
total emissions of metals in the Sudbury Basin. The low level metal emissions as
mocisured simultaneously with the particulates were prorated to a typical
production of nickel bessemer matte and blister copper (12, 14, 17, 20, 21) and
the prorated emissions from various process steps are shown in Table 14.
The accuracy of these emission measurements was low, for reasons already
discussed under particulate emission measurements, hence, the degree of
representativeness of emissions in Table 14 is not known. However, they are the
best measurements presently available and at least accurate enough to confirm
what was suspected before; that is, in comparison to the other sources discussed
in this report, the low level emissions from the smelter building are not a
significant contributor to the total metal emissions in the Sudbury Basin, with
the exception of copper.
7.4 THE FALCONBRIDGE 93 M STACK
Emissions of metals from the Falconbridge smelter were measured with
TABLE it*: AVERAGE LOW LEVEL EMISSIONS OF METALS IN KILOGRAMS
FROM THE INCO SMELTER AT COPPER CLIFF DURING TYPICAL PRODUCTION RATES
OF NICKEL BESSEMER MATTE AND BLISTER COPPER IN KILOGRAMS/DAY
T* Total Emissions of Lead, Zinc, Cadmium, Bismuth, Arsenic, and Selenium estimated at 1 Kg/D (17)
T** Total of Lead, Zinc, Cadmium, Bismuth, Arsenic, and Selenium emissions - 1,33 Kg/D (21)
both old and new smelting processes on line. The results suggested that there
was a significant decrease in emissions of at least the major metals occurred
after the installation of the new process in 1978, Admittedly, the measurement
methods prior to 1978 were not as accurate as the multipoint in-stack sampling
executed at the 93 m stack in 1978, and the results may be in error. In 1973, an
in-stack-single-point grab sample was taken (23), while a comprehensive in-
plume method wcis employed in 1977 (15). The in-plume method can also
underestimate the emissions of nonvolatile metals, as discussed under the metal
emissions from the 19^ m stack; hence, the emissions of these metals from the
old process could have been even higher than measured and shown in Table 15. In
spite of this possible underestimation, it is clear from Table 15 that the metal
emissions from the smelter have been significantly reduced after the installation
of the new process.
There is a degree of similarity in the size distribution of metals emitted
from the Falconbridge 93 m and Inco 381 m stacks; iron, nickel and copper are
emitted at a larger size than the more volatile lead and zinc. However, in terms
of absolute size, all metal particles from the Falconbridge stack were smaller,
with the mass median diameters for iron, nickel and copper ranging from 3.0 to
7.0 micrometers (26) and 0.5 to 0.9 micrometers for lead and zinc; comparable
values at the Inco 381 m stack were larger than 13.0 micrometers for non-
volatile metals, and 0.5 to 4.0 micrometers for lead and zinc.
No correlation or dependence of metal emissions on production at the
Falconbridge smelter can be shown because of an insufficient number of
TABLE 15: EMISSIONS OF METALS FROM THE FALCONBRIDGE 93 M STACK IN KILOGRAMS/DAY
8. EMISSIONS OF SULPHURIC ACID
The difficulties inherent in determining sulphuric acid in emissions from
mineral processing were already discussed in the description of sampling
methods. Consequently, a possibility exists that some of the measured
emissions, with the exception of acid plants, are in error. This possibility was
recognized after detailed analyses of test data, which were not always consistent
with either theoretical expectations or other measurement programs (^, 11). In
most instances, inconsistencies were traced to improper sampling conditions and
low sampling temperatures which allowed condensation of sulphuric acid on
particulates and, hence, possible formation of artifact sulphates. Sulphates
including those of artifact origin, were excluded from the calculations of acid
emissions, and so calculated emissions could have been underestimated. The
total sulphate emissions from the 381 m stack were in some tests as large as the
sulphuric acid emissions (16). There are no similar interferences in the acid
plant emissions, and these emissions can be considered accurate.
Depending on the source, the acid emissions account for OA to 3,0 percent
of the total sulphur dioxide and acid emissions. In the Inco 381 m stack and the
Falconbridge 93m stack emissions, these percentages range from OA to lA,
while in the Inco 194 m stack, the percentage is higher at atwut 3%. The largest
source of acid emissions is the 381 m stack, contributing about 77% to the total
of 25.9 tonnes of acid per day from all major sources in Sudbury, as indicated in
Hourly emissions from cdl sources are shown in Table 16.
TABLE 16: ACID EMISSIONS FROM MAJOR INDUSTRIAL SUDBURY
SOURCES IN TONNES/HOUR
Inco 381 m
Inco 194 m
Falconbridge 93 m
Add emissions from the 381 m smokestack were not always consistent with
sulphur dioxide emissions. Sulphur dioxide emissions were higher in 1977 than in
1973 when acid emissions were higher, thus causing problems in developing a
satisfactory correlation between the emissions of these two species. However,
data from 1973 through 1976 suggest that the emissions of these two species
increase simultaneously (1 through 7).
From among the three processes contributing to the 194 m stack emissions,
the acid plants are the most significant source of acid. Combined emissions
from the three acid plants were 0,1325 tonnes per hour, representing about 71%
of the total to the stack, followed by the nickel refinery with 0.044 tonnes per
hour, and the iron ore recovery plant with 0.01 tonnes per hour. Emissions from
the nickel refinery are not continuous, and the daily maximums occur in three
one- hour periods.
Determination of sulphuric acid in the Inco smelter low level emissions was
not complete in that no satisfactory measurements were performed at the nickel
and the copper converters. No sulphuric acid was found in the fugitive emissions
from the roasters. The emissions listed in Table 16 include only the
reverberatory furnaces and the copper flash furnace.
1. Interim Report on the Inco 1250 Foot Stack Emission Study, Air Resources
Branch, November 23, 1973.
2. Smelter Roof Monitor Emissions 197^ Campaign, Inco Process Technology,
Smelter Project No. 0^7 J, March 10, 1975.
3. Superstack Emissions Monitoring 197^ Campaign - Comparison of Single vs.
Multi-point Sampling, Report, Inco Process Technology, Smelter Project
No. 0^7.6, March 10, 1975.
k. Determination of Sulphuric Acid in Stack Gas, report, Inco Process
Technology, Smelter Project No. 0^7.9, March 2k, 1976.
5. Superstack Emissions Monitoring 1975 Campaign, Comparison of Single vs.
Multi-point Sampling, Report, Inco Process Technology, Smelter Program
No. 0^7-10, April 1^*, 1976.
6. Report on a Source Test at 1250 Foot Inco Stack on June 11, 1975, Air
Resources Branch, Report 07-75, September, 1975.
7. Acid Particulate and Particle Sizing Sampling at Inco Superstack, Sept.,
1976, Air Resources Branch Report No. ARB-TDA-39-77, May, 1977.
8. Tail Gas Analysis Report by C. Cordon, K. Payne, R. Knapp, C.I.L. Report
9. Determination of the Quantity and Nature of Emissions from the NRC
Main Flue to the lORP, Report, Inco Process Technology, Project No.
^1^.8, January 10, 1977.
10. Iron Ore Recovery Plant Main Flue Sampling Report, Inco Process
Technology, lORP, Project No. 226.1^, January 1^, 1977.
11. Acid Particulate and Particle Sizing Sampling at Inco Superstack, June,
1977, Air Resources Branch, Report No. ARB-TDA-53-78, February, 1978.
12. Monitoring of Fugitive Emissions of SO , Particulates in no. 15 Copper
Converter Ventilator, Report, Inco Process Technology, C.C, Smelter
Project No. 0^7.12, June i, 1978.
13. Smelter SO^ Emissions Summaries, Letter from Falconbridge to M.O.E.
Sudbury District Office, December 15, 1977, April 26, 1977 and December
ik. Monitoring of Fugitive Emissions of Sulphur, Particulate and Acid Mist in
No, k Converter Roof Ventilator, Report, Inco Process Technology, Smelter
Project No. 0^7.12, November 9, 1979.
15. Airborne Investigations of the Inco and Falconbridge Stack Plumes, 1976 -
77, Air Resources Branch, Report No. ARB-TDA 60-79, May, 1979.
09. REFERENCES (Cont'd)
16. 380 m Chimney Emissions Monitoring - 16 Particulate and Acid
Determinations (July - October, 1979), Report, Inco Process Technology,
C.C. Smelter Project No. 0*7.17, December 18, 1979.
17. Measurement of Fugitive Emissions of Sulphur Dioxide, Particulates and
Sulphuric Acid from Nickel Reverbertory Furnaces, Report, Inco Process
Technology, Project No. 0*7.12, March 19, 1980,
18. Particle Size Determinations at the 380 M Chimney, Inco Smelter, Copper
Cliff, Ontario, Air Resources Branch, Report No. ARB-TDA-*3-80, 3une,
19. Size Distribution and Emission Rate Measurements of Particulates in the
93 M Falconbrdige Smelter Stack Plume, 1979, Air Resources Branch,
Report No. ARB-TDA 57-80, August 1980.
20. Measurement of Fugitive Sulphur Dioxide, Particulate and Sulphuric Acid
Emissions from Copper Flash Furnace, Report, Inco Process Technology,
Project No. 0*7. 12A, November 19, 1980
21. Measurement of Fugitive Sulphur Dioxide, Particulate and Sulphuric Acid
Emissions from Multiple-Hearth Roaster, Report, Inco Process Technology,
Project No. 0*7- 12B, December 9, 1980.
22. Determination of the Extent of Particulate Stratification at the Inco 381
Meter Chimney at Copper Cliff, Ontario, Air Resources Branch, Report
No. ARB-TDA-58-80, December, 1980.
23. Falconbridge Co. Source Testing 1973, 197* - Smelter Stack, ARB Files,
3uly 19, 1978.
2*. Report and Recommendations of Provincial Officer for Inco Limited
Operations in the Regional Municipality of Sudbury, Ministry of the
Environment, June 21, 1978.
25. Iron Ore Recovery Plcuit, No. 2 Pellet Stack Sampling, Inco Process
Technology, Project No. 226.16, November 1979.
26. Sulphur Dioxide, Sulphuric Acid, Particulate and Particle Size
Determinations at Falconbridge Smelter Stack, August, 1979, Air
Resources Branch, Report No. ARB-TDA-*0-80, December, 1980.
27. Feasibility of Controlling Low Level Emissions from the Copper Cliff
Smelter Complex, Inco Process Technology, Project No. 0*7.21, December
28. Size Distribution and Emission Rate Mesurements of Particulates in the
Inco 381 M Chimney and Iron Ore Recovery Plant 1979-80, Air Resources
Branch, Report No. ARB-TDA-62-80, September, 1980.
29. Comments on Emission Testing Reports Prepared by Inco Smelter Process
Technology, Memoranda to Files, 1977, 1978, 1980, Air Resources Branch.
30. Evaluation of the Modified TBRC Off-Gas Cleaning System; Effect on
Nickel Emissions to lORP Stack, inco Source Testing, July, 1980.
31. Information on Copper Cliff Smelter Electrostatic Precipitators, Letter
from Inco Environmental Control to Northeastern Region of the Ministry of
the Environment, February 21, 1981.
32. 381 Metre Chimney Continuous SO- Monitors - Progress Reports #13 and
//l^f, Inco, December ^, 1981, Nortneastern Region Files, Ministry of the
33. Air Resources Branch Files, Working Notes, 1982.
34. Quarterly Reports from Inco to Sudbury District Office of the Ministry of
35. Airborne Particulate Size Distribution Measurements in Nickel Smelter
Plumes, W. H. Chan et al., for Submission to Atmospheric Environment for
Publication, Mar. 1982.
36. Ontario Source Testing Code, Report //ARB-TDA-66-80, November 1980,
Ministry of the Environment.
37. Code of Federal Regulations, 40 CFR53.4, Protection of Environment,
Revised as of 3uly 1, 1980, Method 5, Office of the Federal Register,
38. Information provided by L. Fitz of the Northeastern Region of the Ministry
of the Environment, Air Resources Branch Working Notes, 1982.
39. Sudbury Environmental Study, Atmospheric Research Program. A Synopsis.
Report y/ ARB-27-82-ARSP, September, 1982.